When you guys seat to touch the rifling how much "touching" are you doing. There is variation in seating depth, so if I seat to just touch some may be sitting .002 off. I would guess this would impact pressure and show up as vertical stringing. Do you seat .005 into the rifling and then essentially let the rifling seat the bullet in the case? I would think this would give a more uniform pressure.
You are using an out of date browser. It may not display this or other websites correctly.
You should upgrade or use an alternative browser.
You should upgrade or use an alternative browser.
Touching the rifling..
- Thread starter 1stmar
- Start date
I had them .010 out, then I chambered a round and had to open the bolt before I fired. The bullet was still in the rifling along with a mess of powder. So I started seating them deeper and the groups opened up.
.005 sounds about right, probably not deep enough for the bullet to grab the rifling yet deep enough for all rounds to touch the rifling.
.005 sounds about right, probably not deep enough for the bullet to grab the rifling yet deep enough for all rounds to touch the rifling.
4runnerman
New member
With 2 thousands neck tension,I seat my bullets long and let the rifle seat them farther when I chamber them. Each rifle and each bullet will differ of course.
I have never seen pressure issues and load a pretty stout load for matches.
30.7 gn RL-15 and 107 Serria match bullets in my 6 BR
I have never seen pressure issues and load a pretty stout load for matches.
30.7 gn RL-15 and 107 Serria match bullets in my 6 BR
green_MTman
New member
if you seat into the rifling you must be prepared to fire the round in the chamber because you wont be able to extract bullet.unless its crimped but you would not crimp that type of load.
what the man a few posts ahead said is true about the bullet being stuck and powder every where.
seat .010 off the grooves and move outward to see if accuracy improves if not go back to .010
.035 off the rifling is also popular as well
what the man a few posts ahead said is true about the bullet being stuck and powder every where.
seat .010 off the grooves and move outward to see if accuracy improves if not go back to .010
.035 off the rifling is also popular as well
4runnerman
New member
1stmar- Put in hammer and give it some soft hits. That will back it out a few thousands then set your dies and reseat them.
green_MTman
New member
what i do is seat a primerless, powderless dumby round with a high COL that will obviously touch the grooves.
have cleaning rod a seating die handy.use the rod to push the bullet out and a little bit at a time seat lower and lower unill you can extract the dumby round.
this means your just off the grooves,so then measure COL and subtract .010 and there go.
unfortunatley you must repeat this process with any new bullet because a certain COL with one bullet being .010 off, does not mean the same for every bullet
have cleaning rod a seating die handy.use the rod to push the bullet out and a little bit at a time seat lower and lower unill you can extract the dumby round.
this means your just off the grooves,so then measure COL and subtract .010 and there go.
unfortunatley you must repeat this process with any new bullet because a certain COL with one bullet being .010 off, does not mean the same for every bullet
Anyone have a method for pulling bullets out of cartridges by a few thousands? I only have a kinetic puller. Looking to avoid recharging a bunch of cases.
I do the same as 4runnerman, a few soft hits and measure. Depending on how many you have to do you'll quickly get down how hard and how many hits are needed.
If you're seating bullets in bottleneck cases that headpace on their shoulder, note they all have a small spread in thousandths in their head to shoulder dimension. That gets transferred to the bullet in the chamber throat.
While you may have seated all the bullets to .0001" tolerance in seater plug contact point to case head, if there's a .004" spread in case head to shoulder measurement, that's the spread (+/- .0001") your bullet will be in the chamber neck. If you had tried to get a .005" bullet jump to the lands, its now got that much spread.
This is why I soft-seat bullets about .010" long for the chamber to ensure they're all set back just right and touching the lands very consistantly. But I size the fired case necks just enough to grip the bullet firmly enough so a chambered round can be ejected and take the bullet with it. Three cheers for dies with different neck diameters for different case neck wall thicknesses.
If you want accurate bullet seating measurements, make them relative to the case shoulder at some reference diameter.
While you may have seated all the bullets to .0001" tolerance in seater plug contact point to case head, if there's a .004" spread in case head to shoulder measurement, that's the spread (+/- .0001") your bullet will be in the chamber neck. If you had tried to get a .005" bullet jump to the lands, its now got that much spread.
This is why I soft-seat bullets about .010" long for the chamber to ensure they're all set back just right and touching the lands very consistantly. But I size the fired case necks just enough to grip the bullet firmly enough so a chambered round can be ejected and take the bullet with it. Three cheers for dies with different neck diameters for different case neck wall thicknesses.
If you want accurate bullet seating measurements, make them relative to the case shoulder at some reference diameter.
Last edited: